<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    .container {
        width: 800px;
        margin: 0 auto;
        display: flex;
    }
    .todo,
    .done {
        width: 50%;
        height: 100%;
    }
    .container h3 {
        height: 50px;
        text-align: center;
        line-height: 50px;
        background-color: #333;
        color: #fff;
    }
    .nav {
        width: 800px;
        height: 100px;
        margin: 0 auto;
        display: flex;
        align-items: center;
    }
    .nav input {
        width: 600px;
        height: 50px;
    }
    .nav button {
        width: 200px;
        height: 50px;
        border: none;
        background-color: orange;
        color: #fff;
    }
    /* .row {
        height: 50px;
        display: flex;
        align-items: center
    }
    .row input {
        margin: 0 10px
    }
    .row span {
        width: 300px;
    }
    .row button {
        width: 50px;
        height: 40px
    } */
    </style>
</head>
<body>
    <div class="nav">
        <input type="text">
        <button>新建任务</button>
    </div>
    <div class="container">
        <div class="todo">
            <h3>未完成</h3>
            <div class="row">
                <input type="checkbox">
                <span>吃饭</span>
                <button>删除</button>
            </div>
        </div>
        <div class="done">
            <h3>已完成</h3>
        </div>
    </div>
</body>
<script>
    function newJob() {
    }
</script>
</html>